The present invention relates to a storage system comprising a plurality of storage areas, and a host computer coupled to the storage system.
Generally, an information system is equipped with a storage apparatus that uses an HDD (hard disk drive) as a storage device, and a storage system including this storage apparatus is accessed from a plurality of host systems (hosts, for example) via a storage area network (SAN: Storage Area Network). Generally, with a storage apparatus, a high-reliability method according to RAID (Redundant Array of Independent (or Inexpensive) Disks) technology is adopted to provide reliability to the storage apparatus beyond the reliability of a stand-alone HDD. Nevertheless, pursuant to the advancement of information society in recent years, the availability (service continuity) of information systems depending on reliability based on RAID is becoming inadequate.
Japanese Patent Laid-Open Publication No. H7-244597 (Patent Document 1) describes high-availability technology to deal with the foregoing situation. This technology prepares a production site and a backup site respectively including a host computer (hereinafter abbreviated as a “host”) and a storage apparatus, and mirrors data stored in the storage apparatus of the production site to the storage apparatus of the backup site. If the storage apparatus of the production site fails and shuts down, application processing that was suspended as a result of such storage apparatus failure is resumed using the storage apparatus and the host of the backup site. This technology is generally referred to as remote copy or remote mirroring.